// ------------------------------------------------------------------------ // Demonstration of derived classes with virtual functionL. // A. Fischer June 15, 1998 file: main.cpp // ------------------------------------------------------------------------ #include "tools.hpp" #include "pqueue.hpp" #include "list.hpp" #include "item.hpp" //#include "linear.cpp" // ------------------------------------------------------------------------ int main( void ) { PQueue P; List L; cout << " Print the empty List L.\n" <